1. Field of the Invention
The present invention relates in general to an apparatus and method for displaying overlapped computer graphics data. More specifically, this invention relates to a full-featured image-processing apparatus and method for displaying overlapped computer graphics data and video data in the desired display areas to faithfully convey the information contents of the displayed data for a multimedia computer system.
2. Description of the Prior Art
In most modern multimedia applications, there is an increasing number of different types of computer graphics data and video data that needs to be processed by a computer graphics processor. "Computer graphics data" herein refers to the graphical images generated by central processing units (CPUs), or graphics processors (sometimes referred to as the "graphics engine") in a computer system. "Video data" refers to the pre-recorded video images imported into the computer. The computer graphics and video data, after been processed by the graphics engine, are directed to an image data selection control device in which a desirable set of computer graphics and video data will be selected for display according to a preset selection model. A digital-to-analog converter then converts the selected computer graphics or video data into analog red, blue and green signals and displays these data on the screen of a monitor.
With the increasing number of different types of computer graphics and video data and the increasingly more complicated conditions for image data selection control, the image data selection control hardware also becomes more and more complex, requiring a large number of logic gates for implementation. Thus, conventional hardware control circuitry can no longer handle all the possible overlapping display conditions. Therefore, approaches using conventional hardware circuitry as the sole graphical display selection mechanism may have insufficient capability to handle today's demanding multimedia applications.